package leetcode;

/**
 * 动态规划：不同路径，有障碍物的初始化
 */
public class Solution41 {
    class Solution {
        public int uniquePathsWithObstacles(int[][] obstacleGrid) {
            int m = obstacleGrid.length;
            int n = obstacleGrid[0].length;
            //创建dp数组
            int[][] dp = new int[m][n];
            if(obstacleGrid[0][0] == 1 || obstacleGrid[m-1][n-1] == 1){
                return 0;
            }
            //既要进行赋值  又要避开障碍物
            for(int i = 0; i < m && obstacleGrid[i][0] == 0 ;i++ ){
                dp[i][0] = 1;
            }
            for(int j = 0; j < n && obstacleGrid[0][j] == 0;j++){
                dp[0][j] = 1;
            }

            for(int i = 1 ;i < m ;i++){
                for(int j = 1; j < n;j++){
                    if(obstacleGrid[i][j] == 0){
                        dp[i][j] = dp[i][j-1] + dp[i-1][j];
                    }else{
                        dp[i][j] = 0;
                    }
                    // dp[i][j] = (obstacleGrid[i][j] == 0) ? dp[i-1][j] + dp[i][j-1] : 0;
                }
            }
            return dp[m-1][n-1];
        }
    }
}
